Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe, network-backed read. The description adds no further behavioral context (result count, rate limits, latency), so it neither enriches nor contradicts the annotation profile.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Purpose is front-loaded in a single efficient paragraph with no filler. The only mild waste is restating the schema's parameter text verbatim, which is redundant rather than harmful.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, return values need not be explained, params are covered, an alternative is named, and annotations carry the safety profile. Complete for a simple two-parameter suggest endpoint, though a note on result scope/limits would round it out.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both parameters are already fully documented. The description repeats the schema text nearly verbatim and adds no new syntax, format, or edge-case meaning, making the baseline 3 correct.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Returns suggested search terms for the given partial keyword') and explicitly names the sibling it is not ('Use appstore_search to search the App Store'). An agent can distinguish autocomplete behavior from full search without opening either schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent to appstore_search for actual searching, and the phrase 'partial keyword ... to autocomplete' implies the when-to-use case. It lacks an explicit when-not clause beyond the sibling pointer, but the context is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.